The paste can be refrigerated in a jar with a tight-fitting lid for up to 3 days.
Sweet, tangy fresh kumquats are about an inch long and oval shaped. Their thin rind is edible, so you don't need to peel them before eating. (The rind is actually sweeter than the pulp.) Closely related to citrus, kumquats range in color from yellow to orange. Believed to be native to China, they are now cultivated in both California and Florida. Look for fresh kumquats in supermarkets from November through March. Frieda's, a mail-order source for specialty produce, has fresh kumquats until June (800-241-1771).